Energy: Forms and Transfer — Answer Key
Part A: Fill in the Blank
Write the missing word or number on each line.
1. When a moving cue ball hits a still eight ball, kinetic energy transfers from one ball to the other.
Grade 4 science teaches that collisions transfer kinetic energy. The cue ball slows or stops, and the eight ball speeds up because energy moved into it.
2. An object falling toward the ground gains kinetic energy because gravity changes its potential energy into motion.
Grade 4 students learn that falling objects transform potential energy into kinetic energy. The lower they fall, the more kinetic energy they have.
3. When a rock falls and hits soil, its kinetic energy spreads into the ground as a small amount of heat and sound.
Grade 4 lessons describe how impact transfers kinetic energy into heat (thermal) and sound energy in the surrounding ground and air.
4. After two cars bump in a parking lot, some kinetic energy turns into sound that you can hear as a crunch.
Grade 4 science teaches that collisions release sound waves. The crunching noise of two cars hitting is kinetic energy turning into sound energy.
5. In a game of pool, a moving ball can transfer kinetic energy to several still balls in one collision.
Grade 4 students learn that energy can spread to multiple objects in one collision. The original kinetic energy splits among the balls that get hit.
6. When a hammer hits a nail, the kinetic energy of the hammer transfers into the nail as motion and a little heat.
Grade 4 science explains that hammer impacts transfer kinetic energy into the nail. Some energy moves the nail, and some becomes heat from friction.
7. A bowling ball rolling into pins shows how kinetic energy can transfer into many smaller objects at once.
Grade 4 lessons use bowling as an example of energy transfer. The ball's kinetic energy spreads to all the pins it strikes during the collision.
8. When a book drops and hits the floor, its kinetic energy turns into sound, heat, and a tiny amount of vibration in the floor.
Grade 4 students learn that impacts cause vibrations in floors. The kinetic energy of the falling book transfers into sound, heat, and small vibrations.
9. A swinging baseball bat transfers kinetic energy into the ball, sending it flying across the field.
Grade 4 science teaches that the bat's kinetic energy moves into the ball during impact. The ball flies because it has gained that energy.
Part B: Matching
Match each item on the left to the correct answer on the right.
1. Match each item to its correct answer.
Cue ball strikes eight ball
→ Kinetic shared between two balls
Kinetic shared between two balls
Apple falls and hits ground
→ Kinetic becomes sound and heat in soil
Kinetic becomes sound and heat in soil
Hammer drives a nail
→ Kinetic transfers into nail and heat
Kinetic transfers into nail and heat
Bowling ball knocks down pins
→ Kinetic spreads to many objects at once
Kinetic spreads to many objects at once
Grade 4 students learn that every collision transfers kinetic energy in a unique way. The shape and number of objects determines how energy spreads.